From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12F25C76192 for ; Tue, 16 Jul 2019 18:42:27 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 7605621743 for ; Tue, 16 Jul 2019 18:42:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7605621743 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-16482-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 16012 invoked by uid 550); 16 Jul 2019 18:42:19 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 15985 invoked from network); 16 Jul 2019 18:42:18 -0000 Date: Tue, 16 Jul 2019 11:41:19 -0700 From: "Paul E. McKenney" To: "Joel Fernandes (Google)" Cc: linux-kernel@vger.kernel.org, Alexey Kuznetsov , Bjorn Helgaas , Borislav Petkov , c0d1n61at3@gmail.com, "David S. Miller" , edumazet@google.com, Greg Kroah-Hartman , Hideaki YOSHIFUJI , "H. Peter Anvin" , Ingo Molnar , Jonathan Corbet , Josh Triplett , keescook@chromium.org, kernel-hardening@lists.openwall.com, kernel-team@android.com, Lai Jiangshan , Len Brown , linux-acpi@vger.kernel.org, linux-doc@vger.kernel.org, linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, Mathieu Desnoyers , neilb@suse.com, netdev@vger.kernel.org, Oleg Nesterov , Pavel Machek , peterz@infradead.org, "Rafael J. Wysocki" , Rasmus Villemoes , rcu@vger.kernel.org, Steven Rostedt , Tejun Heo , Thomas Gleixner , will@kernel.org, "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" Subject: Re: [PATCH 6/9] workqueue: Convert for_each_wq to use built-in list check (v2) Message-ID: <20190716184119.GH14271@linux.ibm.com> References: <20190715143705.117908-1-joel@joelfernandes.org> <20190715143705.117908-7-joel@joelfernandes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190715143705.117908-7-joel@joelfernandes.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-07-16_04:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907160228 On Mon, Jul 15, 2019 at 10:37:02AM -0400, Joel Fernandes (Google) wrote: > list_for_each_entry_rcu now has support to check for RCU reader sections > as well as lock. Just use the support in it, instead of explictly > checking in the caller. > > Signed-off-by: Joel Fernandes (Google) We need an ack from one of the subsystem maintainers on this one. Thanx, Paul > --- > kernel/workqueue.c | 10 ++-------- > 1 file changed, 2 insertions(+), 8 deletions(-) > > diff --git a/kernel/workqueue.c b/kernel/workqueue.c > index 601d61150b65..e882477ebf6e 100644 > --- a/kernel/workqueue.c > +++ b/kernel/workqueue.c > @@ -364,11 +364,6 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq); > !lockdep_is_held(&wq_pool_mutex), \ > "RCU or wq_pool_mutex should be held") > > -#define assert_rcu_or_wq_mutex(wq) \ > - RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ > - !lockdep_is_held(&wq->mutex), \ > - "RCU or wq->mutex should be held") > - > #define assert_rcu_or_wq_mutex_or_pool_mutex(wq) \ > RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ > !lockdep_is_held(&wq->mutex) && \ > @@ -425,9 +420,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq); > * ignored. > */ > #define for_each_pwq(pwq, wq) \ > - list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node) \ > - if (({ assert_rcu_or_wq_mutex(wq); false; })) { } \ > - else > + list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node, \ > + lock_is_held(&(wq->mutex).dep_map)) > > #ifdef CONFIG_DEBUG_OBJECTS_WORK > > -- > 2.22.0.510.g264f2c817a-goog >